Device for mounting a motor assembly of an electric appliance

ABSTRACT

A device (10) for mounting a motor assembly of an electric appliance such as a vacuum cleaner in a housing (2) of the appliance comprises a resilient mounting body (11) which is intended for arrangement between the motor assembly and the housing (2). An inner peripheral portion (12) of the mounting body (11) comprises a first motor contacting portion (13), a second motor contacting portion (14) being provided with axial motor support components (19), and a connection portion (15) interconnecting the motor contacting portions (13, 14). A radial stiffness of the first motor contacting portion (13) is lower than a radial stiffness of the connection portion (15), so that the extent to which vibrations of the motor assembly are coupled into the mounting body (11) at the position of contact to the first motor contacting portion (13) can be at a minimum.

FIELD OF THE INVENTION

The invention relates to a device for mounting a motor assembly of an electric appliance in a housing of the appliance, comprising a resilient mounting body for arrangement between the motor assembly and the housing, wherein the mounting body is designed to contact both the motor assembly and the housing.

The invention further relates to an electric appliance comprising a motor assembly, a housing, and a device as mentioned, wherein the mounting body of the device is arranged between the motor assembly and the housing. In a practical application of the invention, the electric appliance is a vacuum cleaner for removing dust and dirt from surfaces.

BACKGROUND OF THE INVENTION

A device for mounting a motor assembly of an electric appliance in a housing of the appliance is known. In the following, the invention will be explained in the context of a vacuum cleaner, wherein it is noted that an application of the invention in the context of a vacuum cleaner is only one of various possibilities existing within the framework of the invention.

In commonly known vacuum cleaners, an electric motor with an impeller is used to move air so as to create the under-pressure which is necessary for transporting dust and dirt from a surface to be cleaned to a chamber of the vacuum cleaner which is designed to collect and contain the dust and dirt. A motor assembly comprising the electric motor, the impeller and covers is normally arranged in a housing of the vacuum cleaner, wherein the motor assembly is mounted in the housing by means of suspension rubbers which serve for keeping the motor assembly in place. The suspension rubbers may have an additional function in creating air seals at appropriate places between the motor assembly and the housing, so that the suction power of the motor assembly may be used in an optimal manner. In any case, the suspension rubbers also serve for reducing the extent to which vibrations of the motor assembly are transmitted to the housing on the basis of the resilience of the rubber material, which is especially advantageous in view of the desire to let the vacuum cleaner produce as less as possible noise during operation thereof.

According to the prior art, the suspension rubbers are designed with a simple geometry. For example, the suspension rubbers may simply have a ring-like shape, particularly a stepped ring-like shape. Besides suspension rubbers, foam blocks may be used at positions between the motor assembly and the housing. In general, devices used for mounting the motor assembly in the housing comprise a mounting body having resilient properties, wherein the mounting body may comprise rubber or another suitable material. In the simple geometries of the mounting bodies of the known devices, in those cases in which the mounting function of the mounting bodies is combined with a sealing function, a stiffness of the mounting bodies is chosen such as to be a compromise between a requirement of robust mounting and effective sealing on the one hand and a requirement of having only minimal transmission of vibrations during operation of the motor assembly on the other hand. The fact is that the first requirement and the latter requirement contradict each other, the first requirement involving a need of a high stiffness, and the latter requirement involving a need of a low stiffness.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved device for mounting a motor assembly of an electric appliance. The invention is defined by the independent claims. The dependent claims define advantageous embodiments. Preferred embodiments of the invention provide measures for improving a device for mounting a motor assembly of an electric appliance such as a vacuum cleaner in a housing of the appliance in such a way that it is possible to maintain a good mounting function and possibly also a good sealing function of the device on the one hand and to have a reduction of the extent to which vibrations of the motor assembly are transmitted to the housing by the device on the other hand.

According to one aspect of the invention, a device for mounting a motor assembly of an electric appliance in a housing of the appliance is provided, which comprises a resilient mounting body for arrangement between the motor assembly and the housing, wherein an outer portion of the mounting body comprises a housing contacting portion for contacting the housing, and wherein an inner peripheral portion of the mounting body comprises a first motor contacting portion and a second motor contacting portion for contacting the motor assembly at different contacting positions, the first motor contacting portion to contact the motor assembly in at least a radial direction, and the second motor contacting portion to contact the motor assembly in at least an axial direction and being provided with axial motor support components for abutment against the motor assembly in the axial direction, and a connection portion interconnecting the first motor contacting portion and the second motor contacting portion, wherein a radial stiffness of the first motor contacting portion is lower than a radial stiffness of the connection portion.

It follows from the foregoing definition that the mounting device according to the invention is for use in an electric appliance comprising a motor assembly and a housing, and that the device comprises a resilient mounting body having special features aimed at reducing the extent to which vibrations of the motor assembly can be transmitted to the housing of the appliance by the device. Yet, the resilient mounting body is also capable of contacting the motor assembly and the housing, respectively, preferably in a sealing fashion. The fact is that according to the invention, an inner peripheral portion of the mounting body, i.e. a peripheral portion of the mounting body having the smallest diameter when compared to other peripheral portions of the mounting body, comprises three portions, namely the first motor contacting portion, the second motor contacting portion and the connection portion as mentioned, wherein the connection portion interconnects the two motor contacting portions. The overall shape of the mounting body may be an annular shape, in conformity with practical examples of mounting bodies of conventional mounting devices, in which case the inner peripheral portion of the mounting body is an annular inner portion of the mounting body. Preferably, the mounting body is a single, integral piece of material.

Assuming an application of the mounting device according to the invention in an electric appliance as intended, improvements as to the extent to which vibrations of the motor assembly are coupled into the mounting body are realized at the position where the mounting body contacts the motor assembly through the first motor contacting portion. The radial stiffness of the mounting body at that contacting position, which will hereinafter referred to as first contacting position, is chosen so as to be lower than the radial stiffness of the connection portion. As an advantageous consequence, vibrations of the motor assembly acting in the (near) radial direction are picked up by the mounting body at the first contacting position to a much lesser extent as would be the case if the radial stiffness would not be reduced at that contacting position. On the other hand, it is still very well possible to have proper mounting of the motor assembly and a proper sealing function of the mounting body on the motor assembly at the first contacting position, due to factors including the level of radial stiffness of the connection portion and other portions of the mounting body.

Preferably, in order to obtain a significant reducing effect on the transmission of vibrations from the motor assembly to the housing, and thereby a reducing effect on the noise level of the electric appliance, the radial stiffness of the first motor contacting portion is chosen such as to be at least four times lower than the radial stiffness of the connection portion. It is even more preferred if the first stiffness is chosen such as to be at least ten times lower than the latter stiffness. In any case, by having a sufficient difference of stiffness, the need for a high stiffness for mounting the motor assembly and possibly also realizing various sealing effects can be decoupled from the need for a low stiffness for reducing vibration transmission, as it were, wherein the various portions of the mounting body can be optimized independently.

When the invention is applied in the context of vacuum cleaners, an additional advantageous effect is obtained when it comes to reducing the level of vibration transmission through the mounting body of the mounting device, as will now be explained. In the particular context as mentioned, it is a fact that during operation of the appliance, the motor assembly is pulled in the direction of the mounting body under the influence of air intake of the motor assembly at the side of the mounting body. In particular, the housing is provided with a hole for allowing the air intake to take place, a diameter of the hole being chosen such as to be smaller than an outer diameter of the mounting body and larger than an inner diameter of the mounting body. This means that when the motor assembly exerts pressure on the mounting body, an outer portion of the mounting body is squeezed between the motor assembly and a portion of the housing delimiting the hole, while an inner portion of the mounting body is not supported by the housing in any way. Hence, in conventional situations, in which the mounting body has a more or less constant, average stiffness in the radial direction, a certain degree of stiffness of the mounting body is required in order for the mounting body not to be deformed so much under the influence of the pressure that one or more portions thereof would collapse and/or the sealing function would be lost. As explained in the foregoing, this requirement contradicts with the wish to have reduced vibration transmission from the motor assembly to the housing through the mounting body. When the invention is applied, it is preferably so that the inner portion of the mounting body which is not covered by the housing comprises the connection portion and the first motor contacting portion. As the connection portion has a relatively high stiffness and the first motor contacting portion has a relatively low stiffness, the under-pressure is allowed to act on a central portion of the motor assembly which is delimited by the contact to the first motor contacting portion, as the connection portion and other portions of the mounting body may have sufficient stiffness for being capable of withstanding the under-pressure and the pressure which is the result of the displacement of the motor assembly. Contrariwise, in the conventional situations, the entire mounting body is deformed, wherein the under-pressure is allowed to act on a larger central portion of the motor assembly, namely the entire portion which is not covered by the housing. Thus, in the case of the invention, the effect of the under-pressure is limited, so that the movement of the motor assembly under the influence of the under-pressure is limited, and the need for high stiffness of the portions of the mounting body other than the first motor contacting portion to counteract pressures exerted by the motor assembly on the mounting body is limited, as compared to the conventional situations, which allows for more freedom of construction of the mounting body with more possibilities for locally reducing stiffness without deteriorating the mounting function and the sealing function of the mounting body.

In a practical embodiment of the mounting device according to the invention, the first motor contacting portion is located more at an inner periphery of the mounting body, wherein the second motor contacting portion has a larger diameter than the first motor contacting portion. Furthermore, it may be so that the second motor contacting portion is a combined motor/housing contacting portion for contacting the housing in a first axial direction and contacting the motor assembly in a second axial direction opposite to the first axial direction.

In the case of the second motor contacting portion being a combined motor/housing contacting portion as mentioned, it is preferred for the mounting body to be constructed in such a way that a radial position on the mounting body of the axial motor support components corresponds to a position on the mounting body of a radial centerline of an area of the combined motor/housing contacting portion for contacting the housing in the first axial direction. The area of the combined motor/housing contacting portion as mentioned may comprise at least one rib, for example. In case the area comprises two ribs extending alongside each other, for example, the radial centerline as mentioned is the centerline of that combination of two ribs, and extends between the ribs as a consequence thereof, assuming that the ribs are similar.

When the invention is applied in the context of vacuum cleaners, the adaptation as mentioned of the radial position of the axial motor support components to the radial position of the area of the combined motor/housing contacting portion for contacting the housing involves an additional advantageous effect, as will now be explained. In conventional situations, axial support of the motor assembly by the mounting body takes place in an area corresponding to the position of the hole in the housing allowing for the air intake. Thus, axial forces of the motor assembly act on the mounting body in this area, whereas an axial reaction force of the housing acts on the mounting body in another area, namely an area where the mounting body contacts the portion of the housing delimiting the hole. As a result, the mounting body is made to tilt, which adds to the deformation of the mounting body which needs to be compensated for by choosing a certain level of stiffness. In the preferred embodiment of the mounting body, the axial motor support components have a similar radial position as a centerline of the area for contacting the portion of the housing delimiting the hole, so that the axial forces of the motor assembly and the reaction force of the housing act at a similar radial position, and an inclination of the mounting body to tilt is avoided. This is another factor offering possibilities of reduction of stiffness as compared to the conventional situations.

Notwithstanding the foregoing, the mutual positioning of the axial motor support components and the centerline of the area for contacting the portion of the housing delimiting the hole as mentioned is not essential within the framework of the invention. The particular mutual positioning is beneficial in view of having possibilities for reducing stiffness, but it is also possible to choose another positioning, in order to compensate for pressure differences, for example.

In a practical embodiment of the mounting device according to the invention, the second motor contacting portion comprises areas of different radial stiffness, in a pattern along the periphery thereof in which areas of relatively high radial stiffness alternate with areas of relatively low radial stiffness, wherein the axial motor support components are arranged in the areas of relatively low radial stiffness of the second motor contacting portion. In that case, assuming an application of the mounting device according to the invention in an electric appliance as intended, improvements as to the extent to which vibrations of the motor assembly are coupled into the mounting body are realized at two positions where the mounting body contacts the motor assembly, namely the first contacting position on the first motor contacting portion as mentioned earlier and a second contacting position on the second motor contacting portion, particularly the position where axial stiffness of the mounting of the motor assembly is realized through contact to the axial motor support components. On the basis of the fact that the axial motor support components are arranged in the areas of relatively low radial stiffness of the second motor contacting portion, the transmission of vibrations of the motor assembly from the second contacting position to the housing is reduced with respect to a situation in which there would be no areas of relatively low radial stiffness so that the projections would simply extend from areas having an average radial stiffness. In view of the fact that the axial motor support components extend from the areas having relatively low radial stiffness, a situation is obtained at the second contacting position in which axial stiffness and radial stiffness are decoupled, as it were, which allows for optimizing both types of stiffness in the mounting device according to the invention. Even though the axial motor support components extend from the areas of relatively low radial stiffness, a situation in which the components are radially movable to an undesirably large extent is avoided due to the fact that the areas of relatively low radial stiffness are alternated with areas of relatively high radial stiffness.

The mounting body of the mounting device according to the invention may be made of rubber-like materials etc., as known from the art, in order to have sufficient resilience on the one hand for reducing transmittal of vibrations from the motor assembly to the housing through the mounting body and to have sufficient stiffness on the other hand for keeping the motor assembly in place. For the sake of completeness, it is noted that stiffness should be understood such as to relate to the extent to which a piece of material of a certain size and shape is capable of providing constructional strength on the one hand and of deforming/moving under the influence of force on the other hand. High stiffness is associated with high constructional strength and low deformation/movement, whereas low stiffness is associated with low constructional strength and high deformation/movement. Stiffness can be controlled by varying wall thickness, adding ribs in a certain amount and with a certain shape or size, removing material at appropriate places, etc. In general, stiffness of a component is related to resistance of a component to deformation and can be determined by measuring the force which is needed to realize a certain displacement of an area of the component and/or can be determined in a theoretical manner by using suitable techniques such as the finite element method.

The terms “axial”, “radial” and “peripheral” as used in this text are implicitly related to an axis of rotation of the motor and the impeller, and can be understood best in the context of the commonly known annular shape of a mounting body, in a commonly known fashion according to which “axial” refers to a direction along a centerline of the annular shape, wherein “radial” refers to any direction along a radius from the centerline, and wherein “peripheral” refers to any direction around the centerline, which is also commonly referred to as tangential direction. It is noted that the use of the terms as mentioned does not mean that it is essential for the mounting body of the mounting device according to the invention to be annular and/or rotation symmetrical, although this is a practical possibility within the framework of the invention.

In order to realize areas of the second motor contacting portion of the mounting body which are areas of relatively high stiffness, it is practical for the second motor contacting portion to be provided with ribs extending on the mounting body in a substantially radial direction. In the mounting body, the shape and size of the ribs may be chosen so as to realize a degree of stiffness as desired. For example, the stiffness can be controlled by choosing the number of the ribs, choosing dimensions of the ribs and/or choosing a shape of the ribs. In respect of the latter option, it is noted that the ribs may be made to extend in a straight line or in a curved line. In any case, the ribs can be optimized so as to realize radial stiffness as appropriate in a given situation, i.e. as applicable with a certain type of motor assembly and a certain type of electric appliance comprising a housing in which the motor assembly is to be mounted by means of the mounting device according to the invention.

Assuming that the second motor contacting portion is provided with ribs as mentioned in the foregoing, it is practical for the ribs and the axial motor support components to be present at the same side of the mounting body, wherein it is possible for the axial motor support components to be arranged at positions which are positions between the ribs as seen along the periphery of the second motor contacting portion of the mounting body, without contacting the ribs. This is one example of a way of decoupling axial stiffness and radial stiffness in the mounting body. In the mounting body, the decoupling is realized by having sufficient space implemented between the ribs and the axial motor support components, may be controlled by choosing an appropriate path length between the ribs and the components. For example, in order to increase the path length, it is possible to provide the components with a groove at the end where they are connected to material of the mounting body.

Preferably, an axial stiffness of the first motor contacting portion is lower than an axial stiffness of the connection portion and the axial motor support components. In that case, the extent to which vibrations of the motor assembly are transferred to the mounting body at the first contacting position is further reduced. The mounting body may be constructed such as to have sufficient axial stiffness at the second contacting position for mounting the motor assembly in a proper manner. In respect of the axial stiffness, it is furthermore noted that if the second motor contacting portion comprises areas of different radial stiffness, the areas of relatively high radial stiffness of the second motor contacting portion may also be areas of relatively high axial stiffness of the second motor contacting portion. In this way, the second motor contacting portion does not only contribute to keeping the first motor contacting portion in place in the radial direction, but also to keeping the first motor contacting portion in place in the axial direction.

In a practical embodiment of the mounting device according to the invention, the first motor contacting portion of the mounting body is shaped like a lip seal, comprising a lip for abutment against the motor assembly. Lip seals are known per se, and are very well suitable to be used for realizing sealing contact between two elements, i.e. the mounting body at the position of the first motor contacting portion and the motor assembly in this case, while being of relatively low stiffness. In this respect, it may be practical for an outer edge of the lip to be thickened with respect to the remainder of the lip. Especially in the context of vacuum cleaners this may be relevant in order to avoid a situation in which the lip is displaced under the influence of under-pressure acting on the lip and is no longer capable of performing its sealing function as a consequence thereof.

The connection portion of the mounting body may be constructed so as to have a gradually increasing wall thickness in a direction from the first motor contacting portion of the mounting body to the second motor contacting portion of the mounting body. In this way, gradually increasing stiffness is realized in a direction from the first motor contacting portion to the second motor contacting portion, which contributes to the reduction of transmittal of vibrations of the motor assembly coupled into the mounting body at the first contacting position to the other portions of the mounting body and the housing in comparison to a situation in which the connection portion would have an overall wall thickness which is adapted to realize a constant stiffness along the connection portion which is as high as the stiffness needed at the interface of the connection portion and the second motor contacting portion.

According to one practical option existing within the framework of the invention, the axial motor support components comprise pillar-shaped projections extending from the second motor contacting portion of the mounting body in the axial direction. It is not essential for all of the components to have the same size and shape, although this is a feasible option. In any case, when the components are shaped like pillars as mentioned, the pillars may be constructed so as to reduce the extent to which vibrations of the motor assembly are coupled into the mounting body at the position of contact between the pillars and the motor assembly to an optimized extent. For example, the pillar-shaped projections may be constructed so as to have a tapered shape, wherein the area of actual contact to the motor assembly is small in comparison to the area where the projections are connected to material of the mounting body, involving a reduction of the extent to which vibrations of the motor assembly are coupled into the mounting body as a result of the contact between the motor assembly and the mounting body at the position of the projections.

In order to further reduce the extent to which vibrations of a motor assembly are transmitted to a housing by the mounting body of the mounting device according to the invention when the device is applied in an electric appliance comprising such a motor assembly and such a housing, measures may be taken to (locally) reduce stiffness of an outer peripheral portion of the mounting body. For example, the outer peripheral portion may be provided with a groove so as to reduce the radial stiffness at a position close to contact of the mounting body to the housing in the radial direction at an outer periphery of the mounting body.

It follows from the foregoing that the invention relates to a device for mounting a motor assembly of an electric appliance in a housing of the appliance. The invention further relates to an electric appliance comprising a motor assembly, a housing, and a device as mentioned, wherein the mounting body of the device is arranged between the motor assembly and the housing, and wherein both the first motor contacting portion and the second motor contacting portion of the mounting body of the device contact the motor assembly. In conformity with that which has already been explained in the foregoing, an example of such an electric appliance is a vacuum cleaner for removing dust and dirt from surfaces, in which case the housing of the appliance may comprise a chamber for accommodating the motor assembly and a chamber for collecting and containing the dust and dirt, the chambers being positioned adjacent to each other, wherein the device may be arranged at the interface of the chambers, the mounting body of the device extending from inside the chamber for accommodating the motor assembly towards the chamber for collecting and containing the dust and dirt, and the mounting body of the device contacting a wall delimiting the chamber for collecting and containing the dust and dirt, at least during operation of the appliance.

The above-described and other aspects of the invention will be apparent from and elucidated with reference to the following detailed description of a device for mounting a motor assembly in a housing of a vacuum cleaner and realizing an air seal between the motor assembly and the housing. The mounting device which is the subject of the detailed description is one example of numerous possibilities existing within the framework of the invention. Also, the field of vacuum cleaners is one example of numerous fields in which the invention is applicable.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which:

FIG. 1 diagrammatically shows a sectional view of a device according to the invention as applied in a housing of a vacuum cleaner for mounting a motor assembly;

FIG. 2 diagrammatically shows a perspective sectional view of the mounting device and a portion of the housing;

FIG. 3 diagrammatically shows a back view of the mounting device;

FIG. 4 diagrammatically shows a detail A of FIG. 3;

FIG. 5 diagrammatically shows a perspective back view of the mounting device;

FIG. 6 diagrammatically shows a sectional view of the mounting device;

FIG. 7 diagrammatically shows a perspective sectional view of a portion of the mounting device; and

FIG. 8 illustrates how a portion of the mounting device comprising a lip seal contacts the motor assembly in a sealing fashion.

DETAILED DESCRIPTION OF EMBODIMENTS

The figures show a device 10 according to the invention, which is adapted to mount a motor assembly 1 in a housing 2 of a vacuum cleaner. FIG. 1 illustrates how the mounting device 10 is intended to be positioned with respect to the motor assembly 1 and the housing 2. The mounting device 10 comprises an annular mounting body 11 made of rubber or another resilient material for arrangement between the motor assembly 1 and the housing 2. The mounting body 11 is constructed so as to contact the motor assembly 1 at one side thereof and the housing 2 at another side thereof. The mounting device 10 is intended to be positioned in the housing 2 at a side of the motor assembly 1 which is normally denoted as being the front side of the motor assembly 1, and the indications “front” and “back” as used in this text should be understood such as to be related to this assumption, without implying any limitation of the scope of the invention. Hence, the side of the mounting body 11 for contacting the motor assembly 1 may be generally denoted as being the back side of the mounting body 11, whereas the side of the mounting body 11 for contacting the housing 2 may be generally denoted as being the front side of the mounting body 11. It is noted that in FIG. 1, a location of another device for mounting the motor assembly 1 at the back side thereof is indicated by means of reference numeral 3. By using both this other mounting device and the mounting device 10 according to the invention in the housing 2, it is possible to realize proper mounting of the motor assembly 1 in the housing 2.

Among other components, the motor assembly 1 comprises an electric motor (not shown), an impeller 4 which is driven by the motor during operation thereof, and a cover 5 of the various components of the motor assembly 1, which may be made of metal, for example. During operation of the motor, air is taken in at the front side of the motor assembly 1 under the influence of rotation of the impeller 4. The way in which a motor assembly 1 of a vacuum cleaner functions is well known, and in view of the fact that the invention does not relate to the motor assembly 1 as such, an explanation of details of the motor assembly 1 is omitted in this text.

In the example as shown in FIG. 1, the housing 2 of the vacuum cleaner comprises two chambers 6, 7, namely one chamber 6 for accommodating the motor assembly 1 and another chamber 7 for collecting and containing dust and dirt to be removed from a surface by means of the vacuum cleaner. In FIG. 1, only a wall of the latter chamber 7 is shown. Both a wall delimiting the first chamber 6 and the wall delimiting the latter chamber 7 may be made of plastic, which does not alter the fact that other materials are feasible as well. The general design of a vacuum cleaner is well known, and in view of the fact that the invention does not relate to that design as such, an explanation of details of the housing 2 and other parts of the vacuum cleaner is omitted in this text.

In general, it is noted that the construction of the mounting body 11 of the mounting device 10 according to the invention is aimed at obtaining a noise level of the vacuum cleaner during operation which is relatively low, particularly by reducing transmission of vibrations from the motor assembly 1 to the housing 2 with respect to conventional situations, without deteriorating other functions of the mounting body 11, particularly the function of keeping the motor assembly 1 in place inside the housing 2, and also a sealing function as will be explained later. Portions of the mounting body 11 involved in contacting the motor assembly 1 have a relatively low stiffness or are directly connected to areas of relatively low stiffness, so that both the extent to which vibrations from the motor assembly 1 are transferred to the mounting body 11 and the extent to which vibrations propagate through the mounting body 11 are reduced. The invention is typically embodied in two portions of the mounting body 11 which are part of an inner peripheral portion 12 of the mounting body 11, namely a first motor contacting portion 13 and a second motor contacting portion 14. In the shown example, the latter motor contacting portion 14 also has a function in contacting the housing 2, and will therefore be referred to as combined motor/housing contacting portion 14. Furthermore, in the shown example, the first motor contacting portion 13 covers a part of the inner portion 12 having the smallest diameters, and the combined motor/housing contacting portion 14 covers a part of the inner portion 12 having larger diameters. The first motor contacting portion 13 and the combined motor/housing contacting portion 14 are interconnected through a connection portion 15, as can best be seen in FIG. 7 and other figures showing a sectional view of the mounting device 10 or a portion thereof.

In the shown example, the first motor contacting portion 13 is shaped like a lip seal and comprises an annular lip or flap 16 for abutment against the motor assembly 1, which abutment may be of a sealing character. On the basis of this particular shape of the first motor contacting portion 13, a first contacting position of the mounting body 11 to the motor assembly 1 of relatively low stiffness, in both a radial direction and an axial direction, is realized. It is noted that within the framework of the invention, the application of a lip seal 16 is not essential, and that it is also possible to have other shapes of the first motor contacting portion 13 involving a relatively low degree of stiffness. The radial position of the first motor contacting portion 13 is maintained by the combined motor/housing contacting portion 14 and the connection portion 15 extending therefrom towards the first motor contacting portion 13, which are constructed so as to have sufficient radial stiffness as will be explained in the following.

At the front side, the combined motor/housing contacting portion 14 is provided with an annular sealing rib 17 for sealingly contacting the wall of the chamber 7 for collecting and containing dust and dirt in a forward axial direction. In this way, leakage of air which would cause loss of effectiveness of the action of the impeller 4 is avoided. During operation, air is taken in at the front side of the motor assembly 1. As a result, under-pressure is created at the front side of the motor assembly 1, under the influence of which the motor assembly 1 is pulled in a forward direction, pressing against the mounting body 11 and thereby pressing the sealing rib 17 against the wall of the chamber 7 for collecting and containing dust and dirt so that the sealing function of the sealing rib 17 is realized/enhanced.

In the shown example, the radial position of the axial motor support components 19 corresponds to the radial position of the sealing rib 17 at the other side of the combined motor/housing contacting portion 14. Within the framework of the invention, it is also possible to have an alternative positioning of the axial motor support components 19 with respect to the sealing rib 17, i.e. a positioning in which the radial position of the axial motor support components 19 deviates from the radial position of the sealing rib 17. In the situation as shown, the pressure exerted by the motor assembly 1 on the axial motor support components 19 during operation is directly transferred to the sealing rib 17, whereas in the alternative situation, the pressure transfer is indirect due to a staggered radial positioning of the axial motor support components 19 and the sealing rib 17, which may be beneficial when it comes to compensating for pressure differences.

At the back side, the combined motor/housing contacting portion 14 is provided with a number of radial ribs 18, i.e. ribs 18 extending in a radial direction, and a number of axial motor support components 19. In the shown example, the radial ribs 18 and the axial motor support components 19 are arranged along the periphery of the combined motor/housing contacting portion 14 in a regular pattern, particularly a pattern in which two interspaced radial ribs 18 are alternated with a single axial motor support component 19. It will be understood that the invention is in no way limited to this exemplary pattern. The radial ribs 18 are thickened portions of the combined motor/housing contacting portion 14, while the axial motor support components 19 project from areas 20 as present between adjacent radial ribs 18, which areas 20 are not as thick as the radial ribs 18 and have a lower stiffness, in both a radial direction and an axial direction, than the radial ribs 18 as a result thereof.

The axial motor support components 19 have a free end for contacting the motor assembly 1 in a backward axial direction. It will be understood that the above-described effect of the motor assembly 1 being pulled forward under the influence of under-pressure prevailing at the front side of the motor assembly 1 also causes the motor assembly 1 to be pressed against the axial motor support components 19. The axial motor support components 19 can have any shape which is suitable for having an axial mounting effect on the motor assembly 1, wherein it is noted that the shape as shown in the figures, i.e. a pillar shape tapering towards the free end, is just one of the many feasible possibilities. A notable aspect of the mounting device 10 according to the invention resides in the fact that the axial motor support components 19 extend from the areas 20 of relatively low stiffness as present between the radial ribs 18, without contacting the radial ribs 18 or any other thickened portion of the mounting body 11. In this way, axial stiffness provided by the axial motor support components 19 is decoupled as much as possible from radial stiffness provided by the radial ribs 18, which is advantageous when it comes to avoiding transmission of vibrations from the motor assembly 1 as coupled into the mounting body 11 at the position of the axial motor support components 19 to the housing 2.

As can best be seen in FIG. 7 and other figures showing a sectional view of the mounting device 10 or a portion thereof, the connection portion 15 has a gradually increasing wall thickness, hence a gradually increasing stiffness, in a direction from the first motor contacting portion 13 to the combined motor/housing contacting portion 14. In this way, it is achieved that the connection portion 15 is capable of providing sufficient stiffness for determining the position of the first motor contacting portion 13 on the one hand, while having a low as possible stiffness at the side where propagation of vibrations is to be avoided as much as possible on the other hand. Furthermore, the stiffness of the connection portion 15, the combined motor/housing contacting portion 14 and other portions of the mounting body 11 other than the first motor contacting portion 13 may be chosen such as to be sufficient for avoiding notable deformation of the mounting body 11 at the position of the connection portion 15, the combined motor/housing contacting portion 14 and those other portions of the mounting body 11.

Within the framework of the invention, it is possible to not only have measures for reducing transmission of vibrations from the motor assembly 1 to the housing 2 at the position of the inner portion 12 of the mounting body 11, but also to have such measures at the position of an outer peripheral portion 21 of the mounting body 11. For example, as illustrated in the figures, it is possible for the outer portion 21 of the mounting body 11 to be provided with an annular groove 22, which is a V shaped groove 22 in the shown example, for locally reducing the radial stiffness, so that a situation in which the mounting body 11 is tightly and rigidly stretched over the motor assembly 1 is avoided. Also, an annular housing contacting portion 23 which is part of the outer portion 21 of the mounting body 11, and which is positioned at the outer periphery of the mounting body 11, may have a relatively small wall thickness in a radial direction so as to have relatively low radial stiffness, wherein the housing contacting portion 23 may be enforced by ribs 24, 25, 26 at appropriate positions, and wherein the arrangement of the ribs 24, 25, 26 may be chosen so as to have an optimal reducing effect on the transmission of vibration from the motor assembly 1 to the housing 2 at the outer periphery of the mounting body 11. In any case, the radial stiffness of the housing contacting portion 23 at the position of the ribs 24, 25, 26 may be chosen so as to be larger than the radial stiffness of the first motor contacting portion 13.

In FIGS. 7 and 8, it can clearly be seen how an outer edge 27 of the lip seal 16 may be thickened with respect to the remainder of the lip seal 16, which is a practical possibility for avoiding a situation in which the outer edge 27 of the lip seal 16 is pulled in a forward direction under the influence of the under-pressure prevailing at the front side of the motor assembly 1 during operation to such an extent that the lip seal 16 flips to an outstretched position instead of a bent position with respect to the connection portion 15 and is no longer capable of performing its sealing function. Furthermore, FIG. 8 illustrates how the lip seal 16 contacts the motor assembly 1 in a sealing fashion.

It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details that are not required for understanding the invention may have been omitted, and not necessarily to scale.

Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word “comprising” does not exclude other steps or elements, and the indefinite article “a” or “an” does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope of the invention.

Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The term “substantially” as used in this text will be understood by a person skilled in the art as being applicable to situations in which a certain effect is intended which can be fully realized in theory but which involves practical margins for its factual implementation. Where applicable, the term “substantially” may be understood such as to be an adjective which is indicative of a percentage of 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

The term “comprise” as used in this text will be understood by a person skilled in the art as covering the term “consist of”. Hence, the term “comprise” may in respect of an embodiment mean “consist of”, but may in another embodiment mean “contain/include at least the defined species and optionally one or more other species”.

A possible summary of the invention reads as follows. A device 10 for mounting a motor assembly 1 of an electric appliance such as a vacuum cleaner in a housing 2 of the appliance is adapted to reduce transmittal of vibrations of the motor assembly 1 to the housing 2. Particularly, an inner peripheral portion 12 of a resilient mounting body 11 of the device 10, which is intended for arrangement between the motor assembly 1 and the housing 2, is constructed so as to comprise a first motor contacting portion 13, a second motor contacting portion 14 being provided with axial motor support components 19, and a connection portion 15 interconnecting the motor contacting portions 13, 14. A radial stiffness of the first motor contacting portion 13 is lower than said stiffness of the connection portion 15, preferably at least four times lower, even more preferably at least ten times lower, so that the extent to which vibrations of the motor assembly 1 are coupled into the mounting body 11 at the position of contact to the first motor contacting portion 13 can be at a minimum. It is advantageous if also an axial stiffness of the first motor contacting portion 13 is lower than said stiffness of the connection portion 15 and the axial motor support components 19. 

1. Device for mounting a motor assembly of an electric appliance in a housing of the appliance, the device comprising a resilient mounting body for arrangement between the motor assembly and the housing, wherein an outer portion of the mounting body comprises a housing contacting portion for contacting the housing, and wherein an inner peripheral portion of the mounting body comprises: a first motor contacting portion and a second motor contacting portion for contacting the motor assembly at different contacting positions, the first motor contacting portion to contact the motor assembly in at least a radial direction, and the second motor contacting portion to contact the motor assembly in at least an axial direction and being provided with axial motor support components for abutment against the motor assembly in the axial direction, and a connection portion interconnecting the first motor contacting portion and the second motor contacting portion, wherein a radial stiffness of the first motor contacting portion is lower than a radial stiffness of the connection portion.
 2. Device according to claim 1, wherein the radial stiffness of the first motor contacting portion is at least four times lower than the radial stiffness of the connection portion.
 3. Device according to claim 1, wherein the radial stiffness of the first motor contacting portion is at least ten times lower than the radial stiffness of the connection portion.
 4. Device according to claim 1, wherein the second motor contacting portion has a larger diameter than the first motor contacting portion.
 5. Device according to claim 1, wherein the second motor contacting portion is a combined motor/housing contacting portion for contacting the housing in a first axial direction and contacting the motor assembly in a second axial direction opposite to the first axial direction.
 6. Device according to claim 5, wherein a radial position on the mounting body of the axial motor support components corresponds to a position on the mounting body of a radial centerline of an area of the combined motor/housing contacting portion for contacting the housing in the first axial direction.
 7. Device according to claim 1, wherein the second motor contacting portion of the mounting body comprises first and second types of areas, a first type of area being of higher radial stiffness than a second type of area, and the areas being arranged according to a pattern along the periphery of the second motor contacting portion in which areas of the first type alternate with areas of the second type, the axial motor support components being arranged in the areas of the second type.
 8. Device according to claim 7, wherein the second motor contacting portion of the mounting body is provided with ribs extending on the mounting body in a substantially radial direction.
 9. Device according to claim 8, wherein the ribs and the axial motor support components are present at the same side of the mounting body, the axial motor support components being arranged at positions which are positions between the ribs as seen along the periphery of the second motor contacting portion of the mounting body, without contacting the ribs.
 10. Device according to claim 1, wherein an axial stiffness of the first motor contacting portion is lower than an axial stiffness of the connection portion and the axial motor support components.
 11. Device according to claim 1, wherein the first motor contacting portion of the mounting body is shaped like a lip seal, comprising a lip for abutment against the motor assembly, and wherein optionally an outer edge of the lip is thickened with respect to the remainder of the lip.
 12. Device according to claim 1, wherein the connection portion of the mounting body has a gradually increasing wall thickness in a direction from the first motor contacting portion of the mounting body to the second motor contacting portion of the mounting body.
 13. Device according to claim 1, wherein the axial motor support components comprise pillar-shaped projection extending from the second motor contacting portion of the mounting body in the axial direction, and wherein optionally the pillar-shaped projections have a tapered shape.
 14. Electric appliance comprising a motor assembly, a housing, and a device according to claim 1, wherein the mounting body of the device is arranged between the motor assembly and the housing, wherein the housing contacting portion of the mounting body contacts the housing, and wherein both the first motor contacting portion and the second motor contacting portion of the mounting body of the device contact the motor assembly.
 15. Electric appliance according to claim 14, being a vacuum cleaner for removing dust and dirt from surfaces, wherein the housing of the appliance comprises a chamber for accommodating the motor assembly and a chamber for collecting and containing the dust and dirt, the chambers, being positioned adjacent to each other, and wherein the device is arranged at the interface of the chambers, the mounting body of the device, extending from inside the chamber for accommodating the motor assembly towards the chamber for collecting and containing the dust and dirt, and the mounting body of the device contacting a wall delimiting the chamber for collecting and containing the dust and dirt, at least during operation of the appliance. 